In a typical high-performance RF receiver, transmitter, or transceiver, the RF front-end circuitry generally resides in a different circuit partition (e.g., integrated circuit (IC), die, etc.) than does the signal-processing circuitry (e.g., baseband). U.S. patent application Ser. No. 10/075,122, referenced above, for example, discloses partitioning techniques for including the RF front-end circuitry in a different circuit partition than the signal-processing digital circuitry.
RF circuitry, such as the RF front-end circuitry, typically includes analog circuitry that has a relatively high sensitivity to noise and interference. Furthermore, the RF circuitry in some applications, for example, in a mobile communication cellular handset, may have to detect signals as small as a few micro-volts in amplitude. A typical RF front-end circuitry includes one or more low-noise amplifiers (LNAs) designed to amplify small RF signals received at an antenna. The performance of the LNAs and, hence, the overall communication apparatus, may suffer as a result of noise and interference from sources external or even internal to the communication apparatus.
In a typical communication apparatus, such as a mobile communication handset, the digital circuitry in the signal-processing circuitry produces digital signals with relatively small rise and fall times, or with fast transitions or sharp edges. Furthermore, those signals often have relatively high frequencies. As a result, their Fourier series or transforms have rich harmonic contents. The harmonics, or higher-frequency Fourier series components, interfere with, and adversely impact the performance of, the RF front-end circuitry. For further discussion of such interference issues, see U.S. patent application Ser. No. 10/075,122, titled “Digital Architecture for Radio-Frequency Apparatus and Associated Methods,” referenced above. One solution constitutes using more than one circuit partition. For example, one partition may include the RF front-end circuitry, while a second partition includes the signal-processing circuitry.
Using more than one partition for the RF front-end circuitry and the signal-processing circuitry, however, has several disadvantages, such as increased component count, size, and overall cost, and more potential for decreased reliability and increased manufacturing failures. A need exists for highly integrated RF apparatus that include a complete radio in one partition, die, IC, etc.